The present invention relates to a lens-fitted film unit with a built-in strobe in which a strobe light emitting frame is rotated so as to change its attitude for photographing with the strobe light or for photographing without the strobe light.
Hitherto, a lens-fitted film unit with a built-in strobe light is on the market. Recently, the competition to reduce the size of the film unit has become more severe between manufacturers. However, the risk of red eye phenomenon caused by the small size of the film unit is increased accordingly.
In the red eye phenomenon, the strobe light passes the pupil of a subject being photographed and reflects on the retina, whereby the pupil is photographed as red due to the red color of the capillaries on the retina. The smaller the angle formed by the line connecting the center of the strobe light with the subject and the line connecting the optical axis of the photographing lens with the subject, the more frequently the red eye phenomenon occurs. The frequency of occurrence of the red eye phenomenon differs greatly depending on an individual or a human race. In the case of the same person, the frequency of occurrence of the red eye phenomenon differs greatly depends on the direction of the eye and the degree of opening of the pupil. However, if the photographing lens, the photographing distance and the subject are assumed on the same conditions, the smaller the distance between the center of the strobe light and the optical axis of the photographing lens, the more frequent the red eye phenomenon takes place.
Therefore, in the excessively small-sized lens-fitted film unit, it may be difficult to avoid the risk of the above-described red eye phenomenon with a strobe light emitting frame merely fixed at the corner of the lens unit.
In order to reduce the red eye phenomenon, Tokukaihei 8-62675 (Japanese Unexamined Patent Publication) discloses the construction that the light emitting frame is slid into the right direction with the view from the front side during photographing with the strobe so that the distance between the center of the strobe light and the optical axis of the photographing lens is expanded.
Also, Tokukaihei 8-122978 discloses the construction that the light emitting frame is made integrally with a part of the back cover and is rotated by 90 degrees by bending the part of the back cover so that the distance between the center of the strobe light and the optical axis of the photographing lens is expanded.
Incidentally, in the lens-fitted film unit, even if photographing with a strobe is conducted for all frames of roll film, photographing with the strobe enough to conduct for 24 or 27 frames may be permissible. Accordingly, the lens-fitted film unit is different from an ordinary camera in that the user can not replace the battery with a spare one. As the operating section on the strobe switch of a conventional lens-fitted film unit, there are a type in which the main switch is turned on by an operating button which is pushed from the front side while the strobe unit is charged, or another type in which the main switch is turned on by the operating lever which is slid transversely so that its tip end is protruded transversely. However, in the type in which the operating button is pushed from the front side, the operating button may be pushed continuously unintentionally while in a bag. On the other hand, in another type of film unit in which the operating lever is slid transversely, the user may forget to return the operating lever to the original position so that the main switch is kept on. In either type, if the main switch is kept on for a long time, the power source of the battery is uselessly consumed. As a result, photographing with the strobe will not be able to be conducted. From the above view points, it is preferable to make the light emitting frame movable during photographing with a strobe.
The first objective of the present invention is to solve the following problems in the type of the strobe that the light emitting frame is protruded so as to expand the distance between the center of the strobe light and the optical axis of the photographing lens in order to reduce the red eye phenomenon as disclosed by Tokukaihei 8-62675 and Tokukaihei 8-122978.
When the light emitting frame is protruded, since the inner mechanism and electric parts are observed from the outside, the appearance is not nice and troubles may be caused by such an exposed construction. To counter this problem, when the light emitting frame is rotated so as to protrude in order to conduct the photographing the strobe, the configuration is structured such that the inner mechanism and electric parts are not observed from the outside.
Further, although an operation member is operated when the light emitting frame is protruded, while when the light emitting frame is housed in from the protruded condition, the light emitting frame is constructed so as to be housed in the unit so as to allow it to push down the top surface of the light emitting frame.
The strobe light emitting frame whose attitude is changed for conducting photographing with strobe or for conducting photographing without strobe is provided with a predetermined strength with a simple construction.
Next, problems to be solved by the present invention in the film unit will be explained.
As discussed before, recently, the competition to reduce the size of the film unit has become more severe among manufacturers and the realization of such a smaller size film unit is requested. For this purpose, it may be considered that in the lens-fitted film unit with a built-in strobe, a cylindrical battery is shifted from the side of a scroll room to be placed beneath the lens barrel together with a main condenser. With this arrangement, the length of the lens-fitted film unit in the longitudinal direction may be shortened by the length corresponding to the diameter of the cylindrical battery. However, since a strobe light emitting section is also shifted inwardly, the distance between the optical axis of the light emitting section and the optical axis of the photographing lens becomes smaller so that red eye phenomenon tends to take place.
Although it is necessary to turn on the strobe switch when photographing with the strobe, if the strobe switch is kept on due to forgetfulness during photographing without the strobe, the battery power source is discharged uselessly, resulting in difficulty in conducting photographing with the strobe.
The main condenser of the strobe is relatively large in size among the parts of the lens-fitted film unit and is placed so as to extend outside the strobe circuit base board. Accordingly, when the main condenser is assembled as the strobe unit in the film unit, it may be hit with some portions, causing the problem that the position of the main condenser is deviated from the predetermined position.
As stated above, if a brush-flocked paper is pasted on the photographing opening section in order to avoid inner surface reflection, cost is raised due to expenses for the parts and the fitting. Then, if a throttle is provided on the inner surface of the photographing opening section, the cost raise may be reduced. However, the throttle may not be sufficient for strong reverse light.
Also, as stated above, it may be necessary to prevent the film in an APS type cartridge from being moved by actuation of shutter release in order to avoid poor photograph degradation in terms of sharpness.
In order to prevent environmental pollution and to reduce cost as much as possible by reducing the number of thrown-away parts, it may be necessary to make it possible to reuse parts and to make it easy to change the image of the film unit.
From the above point of views, the second objective of the present invention is to provide the lens-fitted film unit with the following advantages. The film unit can be made smaller and the red eye phenomenon hardly take place regardless of the small size. The forgetfulness to turn the battery power source off can be avoided. The trouble of the main condenser of the strobe unit hardly occur. The inner wall with which the influence of the inner surface reflection under reverse light may be reduced can be realized at low cost. A photograph with high sharpness can be obtained even with the use of the film in the APS type cartridge. The number of thrown-away parts of the film unit can be reduced and the image of the film unit can be changed easily.